1. Field of the Invention
The invention relates to controlling power consumption in electrical devices having a finite source of energy, such as battery driven devices and, more particularly, to controlling power consumption in the use of computer displays.
2. Description of Related Art
Computer displays face a problem that if some types of display are left running for a long period of time with a particular image formed on the screen, each portion of the image formed on the screen would become more or less permanently etched into the screen. CRT displays are particularly susceptible to this problem.
Screen savers were developed to minimize this type of occurrence. A screen saver program is loaded and activated if a period of time elapses during which nothing is typed or no mouse movement is detected. In short, when a computer is left unattended with no activity, a screen saver would blacken the screen totally, except, perhaps, for a moving display which would cross the screen in an irregular pattern so that the same pattern would not be displayed at the same location on the screen for extended periods of time.
Flat panel displays, and other types of display also utilize screen saver programs in part to equalize the on and off times of driver circuit elements so that certain driver circuits or light emitting elements were not utilized substantially more than others, aging more rapidly and becoming thus more prone to failure.
Eyetracking devices are known particularly in conjunction with heads up displays in certain control applications in aircraft. An eyetracker device monitors the eyes of a user and calculates the direction in which the user is looking and, in some applications, the particular point in three dimensional space on which the user""s eyes focus.
One commercial eyetracker is the Dual-Purkinje-Image (DPI) Eyetracker, manufactured by Forward Optical Technologies, Inc. of El Chaon, Calif. It determines the direction of gaze over a large two dimensional visual field with great accuracy and without any attachments to the eye. It operates with infra-red light which is invisible to the subject and does not interfere with normal vision. The eyetracker has a pointing accuracy on the order of one minute of arc and response time on the order of one millisecond. One can utilize the DPI Eyetracker with an infra-red optometer to allow a continuous measure of eye focus, producing a three dimensional eyetracker.
The Problems
The prior art has failed to adequately address the need for controlling power consumption in electrical devices having a finite source of energy, e.g. in battery driven devices such as computer displays. In such devices, power is frequently wasted by permitting the device to continue to run even though no user is in the vicinity. In the context of a computer display, display power is certainly wasted if no one is looking at the display. In addition, in the prior art, when a screen saver switches on, and the screen suddenly goes black, a user, in the vicinity of the display, has his attention abruptly distracted toward the screen which switched off.
There is thus a need for improving the control of power consumption in electrical devices, particularly in computer displays. There is also a need for improving the way in which screen savers are activated.
The present invention provides apparatus, processes, systems and computer program products which have the overcome the problems of the prior art. This is achieved by detecting when a user""s attention is directed to the electrical device and reducing the power consumption when his attention is not so directed. It is also directed to detecting the absence of a user in the vicinity of the electrical device and shutting down power consumption to an even greater level when that occurs. When a user returns, power is automatically reapplied.
The invention is directed to apparatus for automatically applying power to an electrical device, including a motion detector, a proximity detector and an optional infrared (IR) detector, activated by the motion detector""s detecting motion, and a switch connected to a source of power and to the electrical device and controlled by the motion detector and the proximity detector for applying power to the electrical device when the proximity detector detects an object within a predetermined distance from the electrical device while it is activated by the motion detector. A power off timer, activated when power is applied to the electrical device, is reset by the motion detector""s detecting motion. It may be used for controlling the switch to remove power from the electrical device when the timer times out.
The invention is also directed to a computing device having a processor, a display having a controllable intensity, an eyetracker providing a signal indicating where a user""s eyes are looking and a control for changing intensity of the display based on that signal. The control reduces the intensity gradually when a user looks away from the display so as not to distract the user. When the user""s eyes return to the display for a predetermined period of time, the control reestablishes the intensity level of the display in effect before the user looked away. The user""s eyes returning to the display can be an instantaneous return, an return to the screen for a predetermined time interval or when the user""s eyes fix on a particular point on the screen. Alternatively, the intensity level can be reestablished when the user""s eyes begin to move toward the display. Power to the eyetracker is removed when the user has not looked at the display for a predetermined period of time.
The invention also relates to a method for automatically applying power to an electrical device, by detecting motion, by detecting proximity of objects to the device; and by applying power to the device when an object is within a predetermined distance from the electrical device within a predetermined period of time after motion has been detected.
The invention also relates to a method of controlling intensity of images on a display, by detecting where a user""s eyes are looking and by changing intensity of images on the display based on where a user""s eyes are looking.
The invention is also directed to a computer system including a network, a plurality of computers connected to the network, one of which is a computer equipped with a motion detector a proximity detector activated by the motion detector detecting-motion; and a switch connected to a source of power and to the electrical device and controlled by the motion detector and the proximity detector for applying power to the at least a particular one of the plurality of computers when the proximity detector detects an object within a predetermined distance from the computer.
The invention is also directed to computer program products each including a memory medium and containing one or more computer programs and data used to implement the above methods, apparatus and systems.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive.